Fluorescence probes study on the mixed cationic-anionic surfactant solutions

Pyrene and p-N, N-dimethylaminostyrylphenylmalononitrile are used as the fluorescence probes to study the micro environment and observe the excimer formation of pyrene in sodium alkylcarboxylate and alkyltrimethyl ammonium bromide mixed solutions. The micro polarity, micro-dielectric constants and micro viscosity of the self-organized assemblies in the mixed cationic-anionic surfactant solution were compared before and after sonication, which may form different organized assemblies (micelle or vesicle). The micelle and vesicles have almost the same polarity for the probing molecules whereas the microviscosity differs. The variation of fluorescence quenching curves also shows the different effect of the change of assembly forms(micelles to vesicles). Thus some novel physicochemical properties about the micro environment of the cationic-anionic surfactant assemblies were found from this report.